Synbranchiformes

Synbranchiformes, often called swamp eels, though that name can also refer specifically to Synbranchidae, is an order of ray-finned fishes that are eel-like but have spiny rays, indicating that they belong to the superorder Acanthopterygii.

==Taxonomy== No synbrachiform fossil is known. The Mastacembeloidei were removed from the Perciformes and added to the Synbranchiformes after a phylogenetic analysis by Johnson and Patterson. These authors consider the Synbranchiformes to be part of a monophyletic group called Smegmamorpha, also containing Mugilimorpha, Atherinomorpha, Gasterosteiformes, and Elassomatidae. Later authors have proposed that the Synbranchiformes along with the Anabantiformes, Carangiformes, Istiophoriformes and Pleuronectiformes form a sister clade to the Ovalentaria which has been called the "Carangimorpharia" but in the 5th Edition of Fishes of the World this clade remained unnamed and unranked.